Charles Kennedy yesterday set out the likely timetable for his return to the centre-stage of politics: a major speech on domestic and foreign affairs at next month's Liberal Democrat conference, followed by an end to his self-imposed silence in Commons debates and a possible front-bench role by late next year.

Kennedy detailed his plans to The Observer in his first national newspaper interview since he was forced to resign as Liberal Democrat leader last January after admitting to a drink problem.

He was careful to avoid any criticism of Sir Menzies Campbell, his former deputy who succeeded him as leader. 'There is no question mark over his position,' Kennedy said. 'He has a very healthy majority achieved with a high proportion of party members participating in the leadership election.'

But amid media criticism of Campbell's Commons performances, with his personal poll ratings only a third of Kennedy's at his peak, and grassroots anger at having been denied a say in the former leader's ousting, the comments will redouble pressure on Campbell before the mid-September party conference. Campbell himself, asked last week about a possible Kennedy return to the front bench, said he had a rare ability among contemporary politicians to connect with ordinary people.

Kennedy, relaxing with his wife, Sarah, and their year-old son at his childhood croft home in Scotland, confessed to 'obvious mixed feelings' about no longer being leader. But he said that on balance 'the credits' outweighed the regrets. He had just returned from France and the first 'really normal family holiday' since his marriage in the summer of 2002, interrupted only by editing a magazine devoted to the party conference and working on his speech. He had spent the months since January helping by-election candidates, travelling to Russia to meet opposition leader Grigory Yavlinsky, who will be the principal overseas speaker at the Lib Dem conference, working on a recent Channel 4 documentary on British politics, and 'trying not to get in the way' of Campbell and his new front-bench team.

Keenly aware of a biography due to be published the week of the Lib Dem conference that will reportedly detail stories of his drink problem, Kennedy reflected, with no sign of rancour, on the 'slight irony' that by the time of his resignation he and a medical adviser were 'satisfied that the issue was under control'. Having said publicly at the time that he was 'healthy and it is up to me to keep it that way,' he said: 'That is still the case. But what I had been trying to do until then was to retain a degree of privacy. I think I am right to continue to deal with it with a degree of privacy, and that people will be fair-minded about that.'

While some former party leaders have shifted gears and gone into writing, teaching or business, Kennedy - who entered the Commons as one of the youngest MPs, aged 23, in the 1983 election - made clear that politics would remain at the centre of his life. 'I've never been tempted during this year since stepping down to do anything else,' he said.

His forced resignation had been difficult. 'It is not a set of circumstances you would recommend to any of your best friends,' he said, chuckling. 'But as I said in my resignation speech, I am not one of life's great sentimentalists about politics. I've been in it long enough to know that there are ups and downs, swings and roundabouts, and you just have to appreciate that fact and get on with it. I'm not in any sense crying foul, or wallowing in self-pity. Sarah and I are both pretty down-to-earth, pragmatic people, so I don't think it was quite as searing as it might have appeared from the outside.'

Kennedy did indirectly hint at some resentment at the haemorrhaging of support among many Lib Dem MPs in the days before his resignation. While not naming names, he said: 'There's no doubt that if you go through that experience, it does inform you who your best friends are.'

Kennedy said when the Commons returned from its recess, he would take a more high-profile role. 'I've slightly held back at the Westminster end of things, largely because there were new people and I didn't want to be getting in the way. But I will certainly want to make more parliamentary contributions.'

Noting 'gracious' statements by Campbell and other top MPs that he would be welcome back on the front benches, Kennedy said he did not expect an offer to return in the immediate future. But he said Campbell's public comments suggested that, assuming there was not an early general election, he would reshuffle his team in the second part of next year. That was the 'likely time-scale' for an offer to return - an offer, he made clear, that he was minded to accept.